NEWS OF THE W EEK
CHINA BACKTRACKS ON PLANT CLOSURE ENVIRONMENT: Government may have second thoughts about shutting a p-xylene facility
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PETROCHEMICAL FACILITY in Dalian, China,
is still in operation months after the local government ordered its closure. Commissioned three years ago, the p-xylene plant is owned by the local conglomerate Fujia Group and Dalian Petrochemical, a subsidiary of PetroChina. Last August, the government of the city of Dalian ordered the closure of the facility amid large public protests after a typhoon that nearly flooded it (C&EN, Sept. 26, 2011, page 20). Demonstrators fear that the plant poses a public threat because it is located only 10 miles from the center of Dalian and because JEAN-FRANÇOIS TREMBLAY/C& EN
Fujia’s Dalian p-xylene plant in September 2011.
FAST ATMOSPHERIC REACTIONS CLIMATE CHANGE: Plants may fuel aerosol
formation more quickly than realized
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KEY TYPE of intermediate in atmospheric
chemistry reacts faster to form compounds that produce cooling aerosols than previously realized, according to a report in Science (DOI: 10.1126/science.1213229). The experimental results indicate that the role of green plants—emissions from which help form the intermediates—in combating global warming may be larger than currently understood. Plants emit alkenes, such as isoprene and terpenes, into the air. Alkenes react with ozone to form so-called Criegee intermediates, which are carbonyl oxides with some biradical and some zwitterionic character. The Criegee intermediates go on to react with other airborne chemicals, including NO2 to form NO3• and SO2 to form SO3. Both products help form aerosol particles. Aerosols seed clouds and play a cooling role in the atmosphere by reflecting sunlight. Despite the importance of Criegee intermediates in atmospheric chemistry, their reactions had never been WWW.CEN-ONLIN E .ORG
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several accidents had occurred in local chemical industry facilities earlier last year. But the plant is still running. “They are still supplying their customers; they never stopped,” says Ashish Pujari, director of fibers and fiber feedstocks at the market research firm IHS Chemical in Singapore. Pujari notes that IHS is in regular contact with Fujia. The Dalian government, Pujari believes, made a hasty decision when it ordered the closure and has quietly backtracked since. It’s not unusual for a p-xylene plant to be located near a city, Pujari observes. And local banks would suffer heavy losses on their loans to Fujia if the plant stopped operating, he adds. It would be quite expensive to move the facility to a new location as the Dalian government has suggested, says Zailin Tang, office chief of the Dalian Environmental Protection Volunteers Association, a nongovernmental organization. And it’s unlikely that an ideal location could be found for the plant, he notes. “The government is currently studying the situation in detail,” Tang says. “But where this plant is located now is not that different from how other p-xylene plants are located in other cities throughout the world.” The Dalian government may in the end order the closure or relocation of the plant, Tang observes. But China needs the facility, he says. “It’s a fact that standards of living are rising in China, and we need industrial materials like p-xylene.”—JEAN-FRANÇOIS TREMBLAY
directly observed. A group led by scientists Craig A. Taatjes of Sandia National Laboratories’ Combustion Research Facility and Carl J. Percival of the University of Manchester’s Center for Atmospheric Science, in England, has now closed that gap by reacting CH2I with O2 to produce the Criegee intermediate CH2OO and studying its chemistry using tunable synchrotron photoionization mass spectrometry. The ability to tune the light used for ionization was critical for the experiments, Taatjes says, because that allowed the researchers to distinguish the Criegee intermediate from formic acid and other isomers. Taatjes, Percival, and colleagues found that although CH2OO reacts with H2O at roughly the same rate as previously believed, it reacts with NO2 and SO2 at rates that are 50 to 10,000 times faster than those estimated in current atmospheric models. The faster rate constants mean that plants might play a more significant role in cooling the atmosphere than realized. The new research demonstrates that “it’s even more important to preserve the biosphere” than scientists have understood, Percival says. The work is also likely to inspire further research into Criegee intermediates, says University of Reading chemistry professor George Marston in a commentary accompanying the report. He looks forward to a better understanding of why CH2OO reacts with various reagents at different rates, as well as future experiments with more complex intermediates.—JYLLIAN KEMSLEY
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